In forming stations for the manufacture of wood fiberboard there is a demand for distributing glue-coated wood fibers onto a wire or belt to form a layer of a certain definite thickness. The layer of wood fibers is transported by the wire or belt to a press installation, in which the wood fibers by the effect of pressure and temperature are pressed into the form of a coherent board.
A device of this kind is described in Swedish Patent No. 457,729, the object of which is to provide a material web having a uniform material distribution. This is achieved by a carrier gas containing wood fibers being supplied tangentially to a convex surface, where fine grained fibers, by the action of the so-called Coanda-effect follow along with the carrier gas along the convex surface to a first outlet, which opens to an endless permeable web, while coarse grained fibers and lumps follow a substantially straight path to a second outlet, which is connected to a line for re-circulation of the fibers. In connection with the endless web there is provided a suction box for collecting and recycling the carrier gas. Although this arrangement has operated satisfactorily, it was found at certain applications that the carrier gas has caused eddy formation, with non-uniform material distribution as a result thereof.
The present invention has an object of separating the particles from the carrier gas and producing a homogenous layer with uniform distribution of particles across the width of the material web.